Dam, this is reminding me of that cray red hammer with the Plomb wrench handle. At least a couple other members were able to come along with some form of corroborating evidence.
Here's what I think we can say almost 100% for sure, at least in my opinion:
1. The logo is clearly meant to mimic the Herbrand script name.
2. I still think it self evident that the "Her" and the "Shi" prefixes is a play on the words Her and She. It's tongue-in-cheek.
What is essential to any 'crime' is finding the motive. With the red hammer, the motive was finally discovered to be functional to a piece of equipment. Here, I think the evidence leads to only one of two possibilities.
A. It's a 'gag' wrench. It was made as a joke, maybe at the Herbrand factory itself. For now, it was made by parties unknown.
B. It is a competitor's wrench that was made to intentionally mislead a unwitting potential buyer with a vague recollection of what a real Herbrand wrench actually looked like into thinking he was buying the genuine article (in the days before the internet age where information was on your finger tips concerning what is what). I don't know if such practices took place among USA manufacturers back then, but I know in the early days of Asian imports it was done frequently (remember Blackhawke?). To think someone would have come up with a script name like that in complete isolation with no exposure or foreknowledge to the Herbrand logo would be....well, perhaps not impossible, but I think there's a better chance of winning the Powerball.
I think it would be helpful, 3Bay, if you were to take some fione sandpaper to it and get all that black off the wrench so we can clearly see every detail of the darker markings in contrast to a light background. I don't think you'll be hurting any collector value on it, but even enhancing it so the figures can be clearly seen.
So far, it remains a sole, unique artifact with no evidence of any other example. Unlike the mentioned red hammers, wrenches were generally made in quantities for resale to stores. Hopefully, another GJ member will come forward with another example. If no corroborating evidence can be found either in another wrench or in a period ad or catalog, then I lean toward a gag wrench.